Estrogen accelerates G1 to S phase transition and induces a G2/M phase-predominant apoptosis in synthetic vascular smooth muscle cells

The effect of estrogen on the synthetic vascular smooth muscle cell is dual. It promotes proliferation of the cells by accelerating their G1/S phase transition via up-regulating Cyclin D1 and Cdk4; and on the other hand, it induces apoptosis of the proliferating cells by up-regulating Bax through p38-MAPK pathway.